Pusher shoe sortation conveyors are well known for directing articles on the conveyor to a desired path. In general, such sortation conveyors include a longitudinally moving endless conveying surface for carrying articles. Pusher shoes, also referred to as pushers or shoes, are carried by the conveyor, configured to be selectively directed to move across the lateral width of the sortation conveyor by actuation of a switch. The switch directs the pusher from a home path, along an outside edge of the sortation conveyor, onto a divert guide path underlying the conveying surface conveyor. The guide path, typically defined by a guide track, causes the pusher to move laterally so as to engage an article and divert it onto a spur conveyor.
With dual sided sorters, there are laterally aligned spur conveyors so that articles carried on the conveying surface may be selectively diverted to either side as desired. When such alternative divert paths are laterally aligned, there are two oppositely directed divert guide paths which cross under the conveying surface. A crossover switch is required at the intersection to keep the pushers moving on the correct path through the intersection.
U.S. Pat. No. 6,860,376, issued Mar. 1, 2005, and U.S. patent application Ser. No. 10/800,070 filed on Mar. 12, 2004, are hereby incorporated by reference.
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings.